Continuously variable transmission

ABSTRACT

A continuously variable transmission is disclosed for use in rotationally or linearly powered machines and vehicles. The single axle transmission provides a simple manual shifting method for the user. An additional embodiment is disclosed which shifts automatically dependent upon the rotational speed of the wheel. Further, the practical commercialization of traction roller transmissions requires improvements in the reliability, ease of shifting, function and simplicity of the transmission. The disclosed transmission may be used in vehicles such as automobiles, motorcycles, and bicycles. The transmission may, for example, be driven by a power transfer mechanism such as a sprocket, gear, pulley or lever, optionally driving a one way clutch attached at one end of the main shaft.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/006,409, filed Dec. 6, 2004, which is a continuation of U.S.application Ser. No. 10/418,509, filed Apr. 16, 2003, now U.S. Pat. No.6,945,903, which is a continuation of U.S. application Ser. No.10/141,652, filed May 7, 2002, now U.S. Pat. No. 6,551,210, which is acontinuation of U.S. application Ser. No. 09/695,757, filed Oct. 24,2000, now U.S. Pat. No. 6,419,608, which issued Jul. 16, 2002. Each ofthe above identified applications is incorporated by reference in itsentirety.

The U.S. application Ser. No. 10/418,509 is also a continuation-in-partof U.S. application Ser. No. 10/016,116, filed on Oct. 30, 2001, nowU.S. Pat. No. 6,676,559, which is a continuation of U.S. applicationSer. No. 09/823,620, filed Mar. 30, 2001, now U.S. Pat. No. 6,322,475,which is a continuation of U.S. application Ser. No. 09/133,284, filedAug. 12, 1998, now U.S. Pat. No. 6,241,636, which in turn claimspriority to U.S. provisional application No. 60/062,860, filed on Oct.16, 1997; U.S. provisional application No. 60/056,045, filed on Sep. 2,1997; U.S. provisional application No. 60/062,620, filed on Oct. 22,1997 and U.S. provisional application No. 60/070,044 filed on Dec. 30,1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The field of the invention relates to transmissions. More particularlythe invention relates to continuously variable transmissions.

2. Description of the Related Art

In order to provide an infinitely variable transmission, varioustraction roller transmissions in which power is transmitted throughtraction rollers supported in a housing between torque input and outputdiscs have been developed. In such transmissions, the traction rollersare mounted on support structures which, when pivoted, cause theengagement of traction rollers with the torque discs in circles ofvarying diameters depending on the desired transmission ratio.

However, the success of these traditional solutions has been limited.For example, in U.S. Pat. No. 5,236,403 to Schievelbusch, a driving hubfor a vehicle with a variable adjustable transmission ratio isdisclosed. Schievelbusch teaches the use of two iris plates, one on eachside of the traction rollers, to tilt the axis of rotation of each ofthe rollers. However, the use of iris plates can be very complicated dueto the large number of parts which are required to adjust the irisplates during shifting the transmission. Another difficulty with thistransmission is that it has a guide ring which is configured to bepredominantly stationary in relation to each of the rollers. Since theguide ring is stationary, shifting the axis of rotation of each of thetraction rollers is difficult. Yet another limitation of this design isthat it requires the use of two half axles, one on each side of therollers, to provide a gap in the middle of the two half axles. The gapis necessary because the rollers are shifted with rotating motioninstead of sliding linear motion. The use of two axles is not desirableand requires a complex fastening system to prevent the axles frombending when the transmission is accidentally bumped, is as often thecase when a transmission is employed in a vehicle. Yet anotherlimitation of this design is that it does not provide for an automatictransmission.

Therefore, there is a need for a continuously variable transmission witha simpler shifting method, a single axle, and a support ring having asubstantially uniform outer surface. Additionally, there is a need foran automatic traction roller transmission that is configured to shiftautomatically. Further, the practical commercialization of tractionroller transmissions requires improvements in the reliability, ease ofshifting, function and simplicity of the transmission.

SUMMARY OF THE INVENTION

The present invention includes a transmission for use in rotationally orlinearly powered machines and vehicles. For example the presenttransmission may be used in machines such as drill presses, turbines,and food processing equipment, and vehicles such as automobiles,motorcycles, and bicycles. The transmission may, for example, be drivenby a power transfer mechanism such as a sprocket, gear, pulley or lever,optionally driving a one way clutch attached at one end of the mainshaft.

In one embodiment of the invention, the transmission comprises arotatable driving member, three or more power adjusters, wherein each ofthe power adjusters respectively rotates about an axis of rotation thatis centrally located within each of the power adjusters, a supportmember providing a support surface that is in frictional contact witheach of the power adjusters, wherein the support member rotates about anaxis that is centrally located within the support member, at least oneplatform for actuating axial movement of the support member and foractuating a shift in the axis of rotation of the power adjusters,wherein the platform provides a convex surface, at least one stationarysupport that is non-rotatable about the axis of rotation that is definedby the support member, wherein the at least one stationary supportprovides a concave surface, and a plurality of spindle supports, whereineach of the spindle supports are slidingly engaged with the convexsurface of the platform and the concave surface of the stationarysupport, and wherein each of the spindle supports adjusts the axes ofrotation of the power adjusters in response to the axial movement of theplatform.

In another embodiment, the transmission comprises a rotatable drivingmember; three or more power adjusters, wherein each of the poweradjusters respectively rotates about an axis of rotation that isrespectively central to the power adjusters, a support member providinga support surface that is in frictional contact with each of the poweradjusters, a rotatable driving member for rotating each of the poweradjusters, a bearing disc having a plurality of inclined ramps foractuating the rotation of the driving member, a coiled spring forbiasing the rotatable driving member against the power adjusters, atleast one lock pawl ratchet, wherein the lock pawl ratchet is rigidlyattached to the rotatable driving member, wherein the at least one lockpawl is operably attached to the coiled spring, and at least one lockpawl for locking the lock pawl ratchet in response to the rotatabledriving member becoming disengaged from the power adjusters.

In still another embodiment, the transmission comprises a rotatabledriving member, three or more power adjusters, wherein each of the poweradjusters respectively rotates about an axis that is respectivelycentral to each of the power adjusters, a support member providing asupport surface that is in frictional contact with each of the poweradjusters, wherein the support member rotates about an axis that iscentrally located within the support member, a bearing disc having aplurality of inclined ramps for actuating the rotation of the drivingmember, a screw that is coaxially and rigidly attached to the rotatabledriving member or the bearing disc, and a nut that, if the screw isattached to the rotatable driving member, is coaxially and rigidlyattached to the bearing disc, or if the screw is rigidly attached to thebearing disc, coaxially and rigidly attached to the rotatable drivingmember, wherein the inclined ramps of the bearing disc have a higherlead than the screw.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cutaway side view of the transmission of the presentinvention.

FIG. 2 is a partial perspective view of the transmission of FIG. 1.

FIG. 3 is a perspective view of two stationary supports of thetransmission of FIG. 1.

FIG. 4 is a partial end, cross-sectional view of the transmission ofFIG. 1.

FIG. 5 is a perspective view of a drive disc, bearing cage, screw, andramp bearings of the transmission of FIG. 1.

FIG. 6 is a perspective view of a ratchet and pawl subsystem of thetransmission of FIG. 1 that is used to engage and disengage thetransmission.

FIG. 7 is partial perspective view of the transmission of FIG. 1,wherein, among other things, a rotatable drive disc has been removed.

FIG. 8 is a partial perspective view of the transmission of FIG. 1,wherein, among other things, the hub shell has been removed.

FIG. 9 is a partial perspective view of the transmission of FIG. 1,wherein the shifting is done automatically.

FIG. 10 is a perspective view of the shifting handlegrip that ismechanically coupled to the transmission of FIG. 1.

FIG. 11 is an end view of a thrust bearing, of the transmission shown inFIG. 1, which is used for automatic shifting of the transmission.

FIG. 12 is an end view of the weight design of the transmission shown inFIG. 1.

FIG. 13 is a perspective view of an alternate embodiment of thetransmission bolted to a flat surface.

FIG. 14 is a cutaway side view of the transmission shown in FIG. 13.

FIG. 15 is a schematic end view of the transmission in FIG. 1 showingthe cable routing across a spacer extension of the automatic portion ofthe transmission.

FIG. 16 is a schematic end view of the cable routing of the transmissionshown in FIG. 13.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following detailed description is directed to certain specificembodiments of the invention. However, the invention can be embodied ina multitude of different ways as defined and covered by the claims. Inthis description, reference is made to the drawings wherein like partsare designated with like numerals throughout. Furthermore, embodimentsof the invention may include several novel features, no single one ofwhich is solely responsible for its desirable attributes or which isessential to practicing the inventions herein described.

The present invention includes a continuously variable transmission thatmay be employed in connection with any type of machine that is in needof a transmission. For example, the transmission may be used in (i) amotorized vehicle such as an automobile, motorcycle, or watercraft, (ii)a non-motorized vehicle such as a bicycle, tricycle, scooter, exerciseequipment or (iii) industrial equipment, such as a drill press, powergenerating equipment, or textile mill.

Referring to FIGS. 1 and 2, a continuously variable transmission 100 isdisclosed. The transmission 100 is shrouded in a hub shell 40 covered bya hub cap 67. At the heart of the transmission 100 are three or morepower adjusters 1 a, 1 b, 1 c which are spherical in shape and arecircumferentially spaced equally around the centerline or axis ofrotation of the transmission 100. As seen more clearly in FIG. 2,spindles 3 a, 3 b, 3 c are inserted through the center of the poweradjusters 1 a, 1 b, 1 c to define an axis of rotation for the poweradjusters 1 a, 1 b, 1 c. In FIG. 1, the power adjuster's axis ofrotation is shown in the horizontal direction. Spindle supports 2 a-fare attached perpendicular to and at the exposed ends of the spindles 3a, 3 b, 3 c. In one embodiment, each of the spindles supports have abore to receive one end of one of the spindles 3 a, 3 b, 3 c. Thespindles 3 a, 3 b, 3 c also have spindle rollers 4 a-f coaxially andslidingly positioned over the exposed ends of the spindles 3 a, 3 b, 3 coutside of the spindle supports 2 a-f.

As the rotational axis of the power adjusters 1 a, 1 b, 1 c is changedby tilting the spindles 3 a, 3 b, 3 c, each spindle roller 4 a-f followsin a groove 6 a-f cut into a stationary support 5 a, 5 b. Referring toFIGS. 1 and 3, the stationary supports 5 a, 5 b are generally in theform of parallel discs with an axis of rotation along the centerline ofthe transmission 100. The grooves 6 a-f extend from the outercircumference of the stationary supports 5 a, 5 b towards the centerlineof the transmission 100. While the sides of the grooves 6 a-f aresubstantially parallel, the bottom surface of the grooves 6 a-f forms adecreasing radius as it runs towards the centerline of the transmission100. As the transmission 100 is shifted to a lower or higher gear bychanging the rotational axes of the power adjusters 1 a, 1 b, 1 c, eachpair of spindle rollers 4 a-f, located on a single spindle 3 a, 3 b, 3c, moves in opposite directions along their corresponding grooves 6 a-f.

Referring to FIGS. 1 and 3, a centerline hole 7 a, 7 b in the stationarysupports 5 a, 5 b allows the insertion of a hollow shaft 10 through bothstationary supports 5 a, 5 b. Referring to FIG. 4, in an embodiment ofthe invention, one or more of the stationary support holes 7 a, 7 b mayhave a non-cylindrical shape 14, which fits over a correspondingnon-cylindrical shape 15 along the hollow shaft 10 to prevent anyrelative rotation between the stationary supports 5 a, 5 b and thehollow shaft 10. If the rigidity of the stationary supports 5 a, 5 b isinsufficient, additional structure may be used to minimize any relativerotational movement or flexing of the stationary supports 5 a, 5 b. Thistype of movement by the stationary supports 5 a, 5 b may cause bindingof the spindle rollers 4 a-f as they move along the grooves 6 a-f.

As shown in FIGS. 4 and 7, the additional structure may take the form ofspacers 8 a, 8 b, 8 c attached between the stationary supports 5 a, 5 b.The spacers 8 a, 8 b, 8 c add rigidity between the stationary supports 5a, 5 b and, in one embodiment, are located near the outer circumferenceof the stationary supports 5 a, 5 b. In one embodiment, the stationarysupports 5 a, 5 b are connected to the spacers 8 a, 8 b, 8 c by bolts orother fastener devices 45 a-f inserted through holes 46 a-f in thestationary supports 5 a, 5 b.

Referring back to FIGS. 1 and 3, the stationary support 5 a is fixedlyattached to a stationary support sleeve 42, which coaxially encloses thehollow shaft 10 and extends through the wall of the hub shell 40. Theend of the stationary support sleeve 42 that extends through the hubshell 40 attaches to the frame support and preferentially has anon-cylindrical shape to enhance subsequent attachment of a torque lever43. As shown more clearly in FIG. 7, the torque lever 43 is placed overthe non-cylindrical shaped end of the stationary support sleeve 42, andis held in place by a torque nut 44. The torque lever 43 at its otherend is rigidly attached to a strong, non-moving part, such as a frame(not shown). A stationary support bearing 48 supports the hub shell 40and permits the hub shell 40 to rotate relative to the stationarysupport sleeve 42.

Referring back to FIGS. 1 and 2, shifting is manually activated byaxially sliding a rod 11 positioned in the hollow shaft 10. One or morepins 12 are inserted through one or more transverse holes in the rod 11and further extend through one or more longitudinal slots 16 (not shown)in the hollow shaft 10. The slots 16 in the hollow shaft 10 allow foraxial movement of the pin 12 and rod 11 assembly in the hollow shaft 10.As the rod 11 slides axially in the hollow shaft 10, the ends of thetransverse pins 12 extend into and couple with a coaxial sleeve 19. Thesleeve 19 is fixedly attached at each end to a substantially planarplatform 13 a, 13 b forming a trough around the circumference of thesleeve 19.

As seen more clearly in FIG. 4, the planar platforms 13 a, 13 b eachcontact and push multiple wheels 21 a-f. The wheels 21 a-f fit intoslots in the spindle supports 2 a-f and are held in place by wheel axles22 a-f. The wheel axles 22 a-f are supported at their ends by thespindle supports 2 a-f and allow rotational movement of the wheels 21a-f.

Referring back to FIGS. 1 and 2, the substantially planar platforms 13a, 13 b transition into a convex surface at their outer perimeter(farthest from the hollow shaft 10). This region allows slack to betaken up when the spindle supports 2 a-f and power adjusters 1 a, 1 b, 1c are tilted as the transmission 100 is shifted. A cylindrical supportmember 18 is located in the trough formed between the planar platforms13 a, 13 b and sleeve 19 and thus moves in concert with the planarplatforms 13 a, 13 b and sleeve 19. The support member 18 rides oncontact bearings 17 a, 17 b located at the intersection of the planarplatforms 13 a, 13 b and sleeve 19 to allow the support member 18 tofreely rotate about the axis of the transmission 100. Thus, the bearings17 a, 17 b, support member 18, and sleeve 19 all slide axially with theplanar platforms 13 a, 13 b when the transmission 100 is shifted.

Now referring to FIGS. 3 and 4, stationary support rollers 30 a-1 areattached in pairs to each spindle leg 2 a-f through a roller pin 31 a-fand held in place by roller clips 32 a-1. The roller pins 31 a-f allowthe stationary support rollers 30 a-1 to rotate freely about the rollerpins 31 a-f. The stationary support rollers 30 a-1 roll on a concaveradius in the stationary support 5 a, 5 b along a substantially parallelpath with the grooves 6 a-f. As the spindle rollers 4 a-f move back andforth inside the grooves 6 a-f, the stationary support rollers 30 a-1 donot allow the ends of the spindles 3 a, 3 b, 3 c nor the spindle rollers4 a-f to contact the bottom surface of the grooves 6 a-f, to maintainthe position of the spindles 3 a, 3 b, 3 c, and to minimize anyfrictional losses.

FIG. 4 shows the stationary support rollers 30 a-1, the roller pins, 31a-f, and roller clips 32 a-1, as seen through the stationary support 5a, for ease of viewing. For clarity, i.e., too many numbers in FIG. 1,the stationary support rollers 30 a-1, the roller pins, 31 a-f, androller clips 32 a-1, are not numbered in FIG. 1.

Referring to FIGS. 1 and 5, a concave drive disc 34, located adjacent tothe stationary support 5 b, partially encapsulates but does not contactthe stationary support 5 b. The drive disc 34 is rigidly attachedthrough its center to a screw 35. The screw 35 is coaxial to and forms asleeve around the hollow shaft 10 adjacent to the stationary support 5 band faces a driving member 69. The drive disc 34 is rotatively coupledto the power adjusters 1 a, 1 b, 1 c along a circumferential bearingsurface on the lip of the drive disc 34. A nut 37 is threaded over thescrew 35 and is rigidly attached around its circumference to a bearingdisc 60. One face of the nut 37 is further attached to the drivingmember 69. Also rigidly attached to the bearing disc 60 surface are aplurality of ramps 61 which face the drive disc 34. For each ramp 61there is one ramp bearing 62 held in position by a bearing cage 63. Theramp bearings 62 contact both the ramps 61 and the drive disc 34. Aspring 65 is attached at one end to the bearing cage 63 and at its otherend to the drive disc 34, or the bearing disc 60 in an alternateembodiment, to bias the ramp bearings 62 up the ramps 61. The bearingdisc 60, on the side opposite the ramps 61 and at approximately the samecircumference contacts a hub cap bearing 66. The hub cap bearing 66contacts both the hub cap 67 and the bearing disc 60 to allow theirrelative motion. The hub cap 67 is threaded or pressed into the hubshell 40 and secured with an internal ring 68. A sprocket or pulley 38is rigidly attached to the rotating driving member 69 and is held inplace externally by a cone bearing 70 secured by a cone nut 71 andinternally by a driver bearing 72 which contacts both the driving member69 and the hub cap 67.

In operation, an input rotation from the sprocket or pulley 38, which isfixedly attached to the driver 69, rotates the bearing disc 60 and theplurality of ramps 61 causing the ramp bearings 62 to roll up the ramps61 and press the drive disc 34 against the power adjusters 1 a, 1 b, 1c. Simultaneously, the nut 37, which has a smaller lead than the ramps61, rotates to cause the screw 35 and nut 37 to bind. This featureimparts rotation of the drive disc 34 against the power adjusters 1 a, 1b, 1 c. The power adjusters 1 a, 1 b, 1 c, when rotating, contact androtate the hub shell 40.

When the transmission 100 is coasting, the sprocket or pulley 38 stopsrotating but the hub shell 40 and the power adjusters 1 a, 1 b, 1 c,continue to rotate. This causes the drive disc 34 to rotate so that thescrew 35 winds into the nut 37 until the drive disc 34 no longercontacts the power adjusters 1 a, 1 b, 1 c.

Referring to FIGS. 1, 6, and 7, a coiled spring 80, coaxial with thetransmission 100, is located between and attached by pins or otherfasteners (not shown) to both the bearing disc 60 and drive disc 34 atthe ends of the coiled spring 80. During operation of the transmission100, the coiled spring 80 ensures contact between the power adjusters 1a, 1 b, 1 c and the drive disc 34. A pawl carrier 83 fits in the coiledspring 80 with its middle coil attached to the pawl carrier 83 by a pinor standard fastener (not shown). Because the pawl carrier 83 isattached to the middle coil of the coiled spring 80, it rotates at halfthe speed of the drive disc 34 when the bearing disc 60 is not rotating.This allows one or more lock pawls 81 a, 81 b, 81 c, which are attachedto the pawl carrier 83 by one or more pins 84 a, 84 b, 84 c, to engage adrive disc ratchet 82, which is coaxial with and rigidly attached to thedrive disc 34. The one or more lock pawls 84 a, 84 b, 84 c arepreferably spaced asymmetrically around the drive disc ratchet 82. Onceengaged, the loaded coiled spring 80 is prevented from forcing the drivedisc 34 against the power adjusters 1 a, 1 b, 1 c. Thus, with the drivedisc 34 not making contact against the power adjusters 1 a, 1 b, 1 c,the transmission 100 is in neutral and the ease of shifting isincreased. The transmission 100 can also be shifted while in operation.

When operation of the transmission 100 is resumed by turning thesprocket or pulley 38, one or more release pawls 85 a, 85 b, 85 c, eachattached to one of the lock pawls 81 a, 81 b, 81 c by a pawl pin 88 a,88 b, 88 c, make contact with an opposing bearing disc ratchet 87. Thebearing disc ratchet 87 is coaxial with and rigidly attached to thebearing disc 60. The bearing disc ratchet 87 actuates the release pawls85 a, 85 b, 85 c because the release pawls 85 a, 85 b, 85 c areconnected to the pawl carrier 83 via the lock pawls 81 a, 81 b, 81 c. Inoperation, the release pawls 85 a, 85 b, 85 c rotate at half the speedof the bearing disc 60, since the drive disc 34 is not rotating, anddisengage the lock pawls 81 a, 81 b, 81 c from the drive disc ratchet 82allowing the coiled spring 80 to wind the drive disc 34 against thepower adjusters 1 a, 1 b, 1 c. One or more pawl tensioners (not shown),one for each release pawl 85 a, 85 b, 85 c, ensures that the lock pawls81 a, 81 b, 81 c are pressed against the drive disc ratchet 82 and thatthe release pawls 85 a, 85 b, 85 c are pressed against the bearing discratchet 87. The pawl tensioners are attached at one end to the pawlcarrier 83 and make contact at the other end to the release pawls 85 a,85 b, 85 c. An assembly hole 93 (not shown) through the hub cap 67, thebearing disc 60, and the drive disc 34, allows an assembly pin (notshown) to be inserted into the loaded coiled spring 80 during assemblyof the transmission 100. The assembly pin prevents the coiled spring 80from losing its tension and is removed after transmission 100 assemblyis complete.

Referring to FIGS. 1, 11, 12, and 15, automatic shifting of thetransmission 100, is accomplished by means of spindle cables 602, 604,606 which are attached at one end to a non-moving component of thetransmission 100, such as the hollow shaft 10 or the stationary support5 a. The spindle cables 602, 604, 606 then travel around spindle pulleys630, 632, 634, which are coaxially positioned over the spindles 3 a, 3b, 3 c. The spindle cables 602, 604, 606 further travel around spacerpulleys 636, 638, 640, 644, 646, 648 which are attached to a spacerextension 642 which may be rigidly attached to the spacers 8 a, 8 b, 8c. As more clearly shown in FIGS. 11 and 12, the other ends of thespindle cables 602, 604, 606 are attached to a plurality of holes 620,622, 624 in a non-rotating annular bearing race 816. A plurality ofweight cables 532, 534, 536 are attached at one end to a plurality ofholes 610, 612, 614 in a rotating annular bearing race 806. An annularbearing 808, positioned between the rotating annular bearing race 806and the non-rotating annular bearing race 816, allows their relativemovement.

Referring to FIG. 15, the transmission 100 is shown with the cablerouting for automatic shifting.

As shown in FIGS. 1, 9, 11, and 12, the weight cables 532, 534, 536 thentravel around the hub shell pulleys 654, 656, 658, through holes in thehub shell 40, and into hollow spokes 504, 506, 508 (best seen in FIG.12) where they attach to weights 526, 528, 530. The weights 526, 528,530 are attached to and receive support from weight assisters 516, 518,520 which attach to a wheel 514 or other rotating object at thereopposite end. As the wheel 514 increases its speed of rotation, theweights 526, 528, 530 are pulled radially away from the hub shell 40,pulling the rotating annular bearing race 806 and the non-rotatingannular bearing race 816 axially toward the hub cap 67. The non-rotatingannular bearing race 816 pulls the spindle cables 602, 604, 606, whichpulls the spindle pulleys 630, 632, 634 closer to the hollow shaft 10and results in the shifting of the transmission 100 into a higher gear.When rotation of the wheel 514 slows, one or more tension members 9positioned inside the hollow shaft 10 and held in place by a shaft cap92, push the spindle pulleys 630, 632, 634 farther from the hollow shaft10 and results in the shifting of the transmission 100 into a lowergear.

Alternatively, or in conjunction with the tension member 9, multipletension members (not shown) may be attached to the spindles 3 a, 3 b, 3c opposite the spindle pulleys 630, 632, 634.

Still referring to FIG. 1, the transmission 100 can also be manuallyshifted to override the automatic shifting mechanism or to use in placeof the automatic shifting mechanism. A rotatable shifter 50 has internalthreads that thread onto external threads of a shifter screw 52 which isattached over the hollow shaft 10. The shifter 50 has a cap 53 with ahole that fits over the rod 11 that is inserted into the hollow shaft10. The rod 11 is threaded where it protrudes from the hollow shaft 10so that nuts 54, 55 may be threaded onto the rod 11. The nuts 54, 55 arepositioned on both sides of the cap 53. A shifter lever 56 is rigidlyattached to the shifter 50 and provides a moment arm for the rod 11. Theshifter cable 51 is attached to the shifter lever 56 through lever slots57 a, 57 b, 57 c. The multiple lever slots 57 a, 57 b, 57 c provide forvariations in speed and ease of shifting.

Now referring to FIGS. 1 and 10, the shifter cable 51 is routed to andcoaxially wraps around a handlegrip 300. When the handlegrip 300 isrotated in a first direction, the shifter 50 winds or unwinds axiallyover the hollow shaft 10 and pushes or pulls the rod 11 into or out ofthe hollow shaft 10. When the handlegrip 300 is rotated in a seconddirection, a shifter spring 58, coaxially positioned over the shifter50, returns the shifter 50 to its original position. The ends of theshifter spring 58 are attached to the shifter 50 and to a non-movingcomponent, such as a frame (not shown).

As seen more clearly in FIG. 10, the handlegrip 300 is positioned over ahandlebar (not shown) or other rigid component. The handlegrip 300includes a rotating grip 302, which consists of a cable attachment 304that provides for attachment of the shifter cable 51 and a groove 306that allows the shifter cable 51 to wrap around the rotating grip 302. Aflange 308 is also provided to preclude a user from interfering with therouting of the shifter cable 51. Grip ratchet teeth 310 are located onthe rotating grip 302 at its interface with a rotating clamp 314. Thegrip ratchet teeth 310 lock onto an opposing set of clamp ratchet teeth312 when the rotating grip 302 is rotated in a first direction. Theclamp ratchet teeth 312 form a ring and are attached to the rotatingclamp 314 which rotates with the rotating grip 302 when the grip ratchetteeth 310 and the clamp ratchet teeth 312 are locked. The force requiredto rotate the rotating clamp 314 can be adjusted with a set screw 316 orother fastener. When the rotating grip 302, is rotated in a seconddirection, the grip ratchet teeth 310, and the clamp ratchet teeth 312disengage. Referring back to FIG. 1, the tension of the shifter spring58 increases when the rotating grip 302 is rotated in the seconddirection. A non-rotating clamp 318 and a non-rotating grip 320 preventexcessive axial movement of the handlegrip 300 assembly.

Referring to FIGS. 13 and 14, another embodiment of the transmission900, is disclosed. For purposes of simplicity, only the differencesbetween the transmission 100 and the transmission 900 are discussed.

Replacing the rotating hub shell 40 are a stationary case 901 andhousing 902, which are joined with one or more set screws 903, 904, 905.The set screws 903, 904, 905 may be removed to allow access for repairsto the transmission 900. Both the case 901 and housing 902 have coplanarflanges 906, 907 with a plurality of bolt holes 908, 910, 912, 914 forinsertion of a plurality of bolts 918, 920, 922, 924 to fixedly mountthe transmission 900 to a non-moving component, such as a frame (notshown).

The spacer extension 930 is compressed between the stationary case 901and housing 902 with the set screws 903, 904, 905 and extend towards andare rigidly attached to the spacers 8 a, 8 b, 8 c. The spacer extension930 prevents rotation of the stationary supports 5 a, 5 b. Thestationary support 5 a does not have the stationary support sleeve 42 asin the transmission 100. The stationary supports 5 a, 5 b hold thehollow shaft 10 in a fixed position. The hollow shaft 10 terminates atone end at the stationary support 5 a and at its other end at the screw35. An output drive disc 942 is added and is supported against the case901 by a case bearing 944. The output drive disc 942 is attached to anoutput drive component, such as a drive shaft, gear, sprocket, or pulley(not shown). Similarly, the driving member 69 is attached to the inputdrive component, such as a motor, gear, sprocket, or pulley.

Referring to FIG. 16, shifting of the transmission 900 is accomplishedwith a single cable 946 that wraps around each of the spindle pulleys630, 632, 634. At one end, the single cable 946 is attached to anon-moving component of the transmission 900, such as the hollow shaft10 or the stationary support 5 a. After traveling around each of thespindle pulleys 630, 632, 634 and the spacer pulleys 636, 644, thesingle cable 946 exits the transmission 900 through a hole in thehousing 902. Alternatively a rod (not shown) attached to one or more ofthe spindles 3 a, 3 b, 3 c, may be used to shift the transmission 900 inplace of the single cable 946.

The foregoing description details certain embodiments of the invention.It will be appreciated, however, that no matter how detailed theforegoing appears in text, the invention can be practiced in many ways.As is also stated above, it should be noted that the use of particularterminology when describing certain features or aspects of the inventionshould not be taken to imply that the terminology is being re-definedherein to be restricted to including any specific characteristics of thefeatures or aspects of the invention with which that terminology isassociated. The scope of the invention should therefore be construed inaccordance with the appended claims and any equivalents thereof.

1. A mechanism for facilitating the adjustment of a speed ratio of acontinuously variable transmission (CVT), the mechanism comprising: ashift rod positioned along a longitudinal axis of the CVT; a sleevemounted coaxially with the longitudinal axis; and wherein the shift rodis coupled to the sleeve to cause an axial translation of the sleeve. 2.The mechanism of claim 1, wherein the shift rod is adapted to translateaxially.
 3. The mechanism of claim 1, further comprising a shift pincoupled to the shift rod and to the sleeve.
 4. The mechanism of claim 1,wherein the shift rod comprises a threaded end.
 5. The mechanism ofclaim 1, further comprising a shaft having a bore adapted to receive theshift rod.
 6. The mechanism of claim 5, wherein the sleeve is mountedcoaxially about the shaft.
 7. The mechanism of claim 6, wherein theshaft comprises a slot adapted to allow a coupling between the shift rodwith the sleeve.
 8. The mechanism of claim 7, wherein the couplingcomprises a shift pin.
 9. A continuously variable transmission (CVT)comprising: an elongated shift rod positioned along a longitudinal axisof the CVT; a sleeve mounted coaxially with the longitudinal axis; andwherein the shift rod is operationally coupled to the sleeve such thatan actuation of the shift rod causes an axial translation of the sleeve.10. The CVT of claim 9, wherein the shift rod is adapted to translateaxially.
 11. The CVT of claim 9, wherein the shift rod comprises athreaded portion.
 12. The CVT of claim 9, further comprising a hollowshaft adapted to receive the shift rod in a central bore of the shaft.13. The CVT of claim 12, wherein the sleeve is mounted coaxially aboutthe shaft.
 14. The CVT of claim 13, wherein the shaft comprises a slotthat provides a passage from the central bore to an external surface ofthe shaft.
 15. The CVT of claim 9, further comprising a shift pincoupled to the shift rod and to the sleeve.
 16. The CVT of claim 15,further comprising a shaft adapted to receive the shift rod and to allowthe shift pin to be coupled to the sleeve.
 17. A method of facilitatingan adjustment of a speed ratio in a continuously variable transmission(CVT), the method comprising: actuating a shift rod that isoperationally coupled to a sleeve; and wherein the actuating of theshift rod causes an axial translation of the sleeve.
 18. The method ofclaim 17, wherein actuating a shift rod comprises an axial translationof the shift rod.
 19. The method of claim 17, wherein a shift pinoperationally couples the shift rod to the shift sleeve.
 20. The methodof claim 17, further comprising coupling the sleeve to a platform havinga convex surface.